Zero. Either I owned enough other games within bundles of interest already, or the choices were split a little too much / the discount tiers a little too rigid. Similarly, some wishlisted games closely related to those bundled were missing (eg, the Wadjet Eye bundle had Gemini Rue but no Primordia or Shardlight). So when in a bundle of 8 games, you already own 3, two others are uninteresting, but the three related ones you want that should be in there aren't, then it tends to push the remaining 2-3 titles below the threshold at which they're worth buying in a bundle format. Happened so many times I lost count.
Still waiting for a plain, ordinary, normal, "boring" sale where you can buy as many / few 50-80% discount games as you want individually without timed "insomnia" / bundle gimmicks...